<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        .out-box{
            border:1px;
        }
        .content-box{
            margin:0 auto;
            width:70%;
            background-color: #0088e4;
            padding:50px 50px;
        }
        .ele{
            width:300px;
            height:200px;
            background-color: #009900;
            margin:50px 50px;
            float:left;
        }
        .right{
            width:300px;
            height:200px;
            background-color: #009900;
            float:right;
        }
        .clear{
            clear:both;
        }

    </style>



</head>
<body>
<div class="out-box">
    <div class="content-box">

        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="ele"></div>
        <div class="clear"></div>


    </div>





</div>






</body>
</html>